Plastic optical fibers used for data transmission are most often supplied in cable form where the cable comprises a plastic fiber core, a thin cladding, and a protective jacket which can include strengthening members. Optical fiber connectors and splices are used with said fibers and are an essential part of optical fiber communications systems. Connectors may be used to join lengths of optical fiber into longer lengths, or to connect optical fiber to active devices such as radiation sources, detectors, repeaters, or to passive devices such as switches or attenuators.
To prepare a termination end, a fiber end is exposed and a connector is clamped, crimped or molded onto the cable jacket with the bare fiber portion being exposed. There are many methods of terminating and finishing a termination end such as using adhesive, polishing or melting.
In the method using adhesive, adhesive is injected into a longitudinal bore of the connector. A fiber end of the cable is received into the connector body with the enclosed fiber projecting along the longitudinal bore of the connector. The adhesive wicks and adheres to the fiber, the connector, and other connector parts to permanently secure the connector and fiber together.
In the epoxy/polish method of connecting the fiber optic to the connector and forming a lens, epoxy is applied to an end of a fiber optic cable which is then inserted into the connector. An exposed portion of the fiber optic cable that extends past the second end or exit end of the connector is then finished by polishing with a grinder. This method is disadvantageous in that scratches are left on the fiber optic degrades quality of light transmission and causes loss of signal and signal distortion.
In the heat-reset method, the stripped portion of the fiber is inserted into the connector resting just within a chamfer adjacent an exit or second end of the connector and is melted in place to fill the chamfer. See U.S. Pat. No. 4,191,447. In another embodiments of the heat-reset method, a portion of exposed fiber optic may extend past an exit or second end of a connector. See for example, U.S. Pat. No. 5,097,522, where the exposed fiber optic end extending beyond the terminal face is melted using a conventional hot plate that advances into the plastic fiber optic cable that is made molten. The molten fiber optic cable tip forms a bulge that settles and lodges into a chamfer or recessed pocket to restrict movement of the fiber from the connector and to also create a lens. However, for each of these prior art reference outside variables caused by human contact can degrade the quality of lens formed at the termination end of the connector.
One type of heating device used in the prior art includes using a hot plate termination tool or hot plate termination oven such as the one distributed by FiberFin Inc. of Yorkville, Ill. This oven may have integrated circuitry to control two cycle functions, a melting cycle and a curing cycle. The heating cycle heats a hot plate of the tool/oven for about 17 seconds as indicated by a red light, while the curing cycle turns off the heat and uses a fan to cool the hot plate running about 5 seconds. In the heating cycle, the plastic fiber optic is made molten to fill the chamfer and then the curing cycle permits the molten plastic to solidify and create a lens at a second end of the connector, if done correctly.
One problem with this prior art device is that the two cycling events are automated and successive and thus no user control means exist. The user must wait for the next melt or red cycle in order to prepare the termination end. Another problem with the heating device of the prior art is identified in its use of malleable lens against which molten fiber optic cables are smoothed. Such malleable lens include lens made of brass or stainless steel. Once these malleable lens of the prior art are blemished, it becomes difficult to clean them without accidentally marking or nicking the surface. A blemish can then transfer undesired marks onto subsequent termination ends. Yet another problem with the prior art involves the fact that said malleable lens are soldered to the hot plate oven making the change or removal of the lens impossible by the end user. In order change or remove the soldered lens, the user must send the hot plate device back to the manufacturer.
In addition to the above cited problems, prior art hot plate termination ovens are further problematic by the fact that it employs malleable albeit smooth and flat lens. Such malleable lens which are conventionally used in the prior art include plated brass lens or stainless steel lens. In the process of creating the termination lens at the termination end of the connector, these brass or stainless steel lens employed in the prior art hot plate termination ovens often become blemished with residue or other material. If the residue is not removed from the lens, the residue may impair the quality of the termination lens and such impairment will then be transferred to termination ends of subsequent termination ends on cable and connector connections. However, the malleable nature of such brass or steel lens make them prone to scratches, thus making cleaning of such lens become futile. Also, once the lens is marred, subsequent termination lens prepared using the tarnished lens are also defective.
Many of the problems associated with the prior art are attributed to manual labor or human error. Thus, though the heat-reset method does not leave scratches on the cable, problems still exist such as alignment issues. Misalignment of fiber optic lens with the connector is one such example of error due to manual labor. When a fiber optic cable is not properly axially aligned with the connector the entire system can cause degrade the quality of light transmission. Also, traditionally, users guide the cable into a connector and then the hot plate oven using only their hand. Thus the chances of impairing alignment due to human action is very high. Another problem with the prior art involves the amount of manual pressure applied to the fiber optic cable as the termination end is prepared. Excess pressure applied to the cable as it is heated and made molten increase the chance that the fiber optic cable can be defective. Yet another uncontrolled problem present to the prior art involves a lack of control over the timing of heat cycle of the hot plate oven. This variable attributes to termination ends having poor light transmission qualities as uncontrolled timing of heat may cause cables to burn or even bubble.
Another problem with use of hot plate ovens of the prior art is that manual preparation of the termination ends lack inconsistency due to human error. Users find it difficult to create termination ends on fiber optic cables wherein the user has to manually guide the cable onto the hot plate tools without assistance. Also, attaining consistency when preparing numerous termination ends is difficult to achieve using the prior art methods and devices. These uncontrolled variables affect the quality of the termination lens created at the termination end.
There is a growing demand, for a system and method for facilitating the creation of fiber optic terminations. Such a system and method should be easy to use. Such a system should enable a user to attain consistent results. For instance, a device is desired that cooperates with a hot plate tool or hot plate oven. A device is further desired that will permit a user to properly align both the fiber optic cable and connector to the hot plate tool or oven to create a lens with little-to-no manual interference. A device is desired that will permit a user to control the activation of the heat cycle of a hot plate tool or oven. A device is also desired that will permit an appropriate amount of pressure to be applied on the fiber optic cable to create a lens with little-to-no manual labor. A device is desired that permits the production of defect free lens with optimal optical qualities. A device is desired that repeatedly and consistently permits the production of defect free lens with optimal optical qualities. Further what is desired is an improved hot plate tool used to create said termination end with optimal optical qualities. Accordingly, what is sought, and what is not provided by the prior art, is a fiber optic connector tooling device that is easy to use and that can provide consistent results. Also what is sought is an improved method of creating termination ends with optimal optical qualities.